Grinding-machine



R. C. MITCHELL.

GRINDING MACHINE.

APPLICATION FILED APR. 22,1918.

Patented Apr. 6, 1920.

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GRINDING MACHINE.

APPLICATION FILED APR; 22, 1918.

Patented Apr. 6, 1920.

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GRINDING MACHINE.

APPLICATION FILED APR. 22, 1918.

1,335,905. Patented Apr. 6, 1920.

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R. C. MITCHELL.

GRINDING MACHINE.

APPLICATION FILED APR. 22, 1918.

1,335,905. I Patented Apr. 6, 19 20.

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RAYMOND C. MITCHELL, OF SPRINGFIELD, OHIO, ASSIGNOR TO THE -WEBST'ER & PERKS TOOL COMPANY, OF SPRINGFIELD, OHIO, ,A CORFORIATION OF OHIO.

GRINDING-MACHIN E.

To all whom it may concern:

Be it known that I, RAYMOND C. MrroH- ELL, residing at Springfield, county of Clark, and State of Ohio, have invented certain new and useful Improvements in Grinding-Machines, of which, the following is a specification.

The present invention relates to grinding machines and in some of its features, more particularly, to universal grinders. The general object is to provide novel and advantageous grinder mechanism especially in the devices for relatively moving, and for the movements of, the grinding wheel an the work. Especial desiderata, among'others, are to provide a construction that is economical from the manufacturing standpoint in simplicity, facility of assemblage, etc;-to secure ease and precision in operation and advantageous variability of operating conditions; and to make easy g the repair, replacement and care of operating parts, especially the gearing. These and other objects I attain by the construction, embodying my invention, hereafter described and cla me 1 j I In the drawings Figure 1 is a front elevation of the grinder; Fig. 2 is a cross-section; Fig. 3 is a plane .section taken just below the slide. Figs. 4 and 5 are front and side elevations of the automatic cross feed controlling parts. Fig. 6 is a detail of a cam shaft.

The generalities of arrangement of the work-holding and grinding mechanisms, as hereinafter shown, conform to practice that is familiar in universal grinders and will need but-little description. Suffice it to say that the bed casting 10zcarries the longi- 'tudinally reciprocable work-table 11 and the stand 20 for the belt-driven grinder wheel 21 that is bodily movable transversely; that the work-table carries a centrally-pivoted swivel table 12, which. can be set and clamped, in known fashion, to present the work axis diagonally to the line of table reciprocation, while the swivel table carries the axially adjustable tail-and-head stocks Specifica-tion of Letters Patent.

Patented Apr. 6, 1920.

Application filed April 22, 1918. Serial No. 230,177.

ranged to permit rotary adjustment of the turn-table to change the angle of presentation of the said grinding wheel 21 to the line of'table reciprocation. derstood that these novel to me nor do requisite to a machine that would embody my invention, but with the usual complemental devices for supplying fluid to the grinding wheel -21 (and the supplemental interior grinderif desired) and other usual refinements, they merely characterize an effective universal grinder, details of which may be widely varied by different manufacturers.

It is highly desirable that the gearing and controlling devices, for reciprocating, changing the speed of, and limiting the movements of, the work-table; and for setting, operating, and limiting the action of, the grinding wheel and the work-table shall be so related that they can be aseneralities are neither .sembled in one or more frame elem'ents de- Y may be made least sensitive to possible variatioiis in expansion, or other disturbances, of the bed. Also it is very desirable that the devices for controlling the cross-feed operations of the grinding wheel shall be simple, effective, conveniently positioned and operable with great precision; and all of these, and further, advantages I attain by my invention. Y

The work-table 11 has, on its under side, the usual rack 16, to be driven througha reducing gear train.17 that isactuated from v a pulley shaft 18, which, as in the construction shown, I prefer shall extend parallel with the table so that the step-pulley 19 may be located in a jog at the rear of one end of the bed, and the pulley shaft may receive Slil)p() 1t)1nthe end wall 10? of said jog.

i 3 III the bedsfront wall I provide an opening 10 and in said end wall portion 10 and opening 10, each opening overlain by a cover plate, respectively designated 24 and 25, each demountably bolted in place. On, and preferably integral with, the frort plate 24, I provide a gear frame 26 for the It will be unregard all of them as wardly from the rear wall of the frame, and

bearing studs 26 are provided at suitable points to accommodate the oross-shafting hereinafter referred to. The gearing mounted in this frame will be positioned to cotiperate with part of the pulley-driven means carried by the end plate and I prefer that the cotiperati'on shall be effected through a positive coupling so that thevtwo plates 24 and 25 at right angles to each other are complementa-l in positioning the drive shaft -;and the main shaft-of the gear ingz h e e -demountable gearing frame, that gives double bearings for all of the crossshaftsfand enables the gearing 17, as a unit, to be removed through the front opening, is very desirable and efficacious, and the interrelation of the two demountable plates, through the shafting gives assured positioning of the parts with minimum *of tooling of large parts and minimum liability to injury or wear due 'to' lack of or loss of proper alinements.

Specifically the cone pulley 19, on itsshaft 18, is mounted on the end plate 25 and through reducing pinion and gear, 32, drives the stub-shaft 33- which, detachably splines into a coupling 34 fast on a lengthwise shaft section 35 Which is j'ournaled in the extension yoke 26 Between the yoke bearings this shaft 35 carries two bevel pinions36, 36, loose thereon, and having clutch-toothed hubs, and between these pinions is a doubleended clutch sleeve 37 rotating with but slidable on the shaft. The pinions constantly mesh with the bevel gear38 on a cross shaft 39 of the gearing 17, so thatas one pinion or the other is clutched to the shaft 35 the cross shaft 39 is driven in accordant direction. A shipper yoke 40, on a rock shaft, 41, that is journaled in=plate 24 and a bracket, 26, serves to throw the clutch member; and a pointed spring-pressed pawl 42 mounted in the rear side of the yoke 26 cotiperates with a roller 42? on the shipper yoke to hold it at one or the other of its extremes of movement. Exteriorly the rock shaft 41 has mounted thereon centrally pivoted loose lever 43, and also a hand-lever 44 fast on the shaft, lever 42 being provided for an automatic functioning of the machine hereinafter described, and hand-lever 44 giv-" ing manual control at all times over the reversal of the direction of drive of cross shaft 39.

The gear train 17 is of suitableform to reduce the speed appropriately to any predetermined ratio to drive shaft speed, and

' sitions, the handlehaving secured to its hollowhub-extension a cam 46 .working against a cam 47 that is fast on slide shaft 48 which bears in the lever hub, carries a shipper- .lever 49 and is pressed by spring 50 in appropriate direction to hold the cams in contact. This shipper lever controls the threeposition movement of a clutch-sleeve 51 that, in its two extremes of movement may engage respectively the pinions 52 and 53 loose on the cross shaft 39, with which shaft the clutch sleeve rotates, but on which, of course, it may slide. The two gear trains that are set in motion by clutching of pin ions 52 and 53 respectively to the crossshaft 39 may be varied in ratio as suits the requirement of the'designer, and preferably each comprises merely spur gears and pinions, each of these trains communicating power to the spur gear 55 that meshes with the table-rack 16. In the particular trains shown, pinion 52 drives gear 56 through the higher-speed parts 56,57, 58 and 59, while from pinion 53 the train of lower ratio runs through 61, 64, 63, 59. A hand wheel to enable the table to be reciprocated manually is provided at 66, working through a stub shaft 67 of the plate and pinions 68 and 62 to drive the low-speed gearing train in either direction.

The, cross-feed shaft 70 extends through the front plate and suitable frame bearings and at its rear end makes suitable worm gearing connection with the vertical shaft 71 that traverses the grinding wheel transversely. Following common practice, the vertical shaft 71 bears a pinion 72 in connection with a rack 73 on the sliding grinder wheel yoke. Further shaft 71 is provided at its bottom with a worm'wheel 74 with which engages a worm 75 on the shaft 70, the end of this worm-shaft being supported in a bracket 76 that depends from the bedtop, so that the worm shaft may be bodilyremoved with the demounting of the front plate, its worm merely slipping out of the bearing bracket 76.

The cross-feed mechanism for automatically indexing the rate and extent of the grinding operations is operated, as is usual, accordantly with the reversals of direction of table travel, and I illustrate, conventionally, adjustable dogs 77 upon the table arranged to strike-confronting head projections 78 and 79 on. the loose lever 43 and hand lever 44 on reversing shaft 41, so that the dogs will give the loose lever 43 a longer positive throw than they do the hand lever relation of the 44 fast on the shaft. At its lower end the lever 43, bears a head 43 downwardly pointed and cooperating with a point'roller 80 on the spring-upheld actuating-link 81 of the automatic cross-feed. When this roller 80 is positioned as shown in the'drawing, approximately vertically below the center of shaft 41, it will be apparent that one dog 77 striking theloose lever, 43, will rock it so that its point passes the point roller 80, and then the loose lever will be cammed by the head to a position opposite to that which it has occupied, so that on the reverse strokeof the table the opposite dog will reverse the as shown in dotted lines in Fig. 4, the roller pointis shifted sufliciently toward one extreme of movement, it will be beyond one limit of throw of the point of head 43 of the loose lever, and therefore the loose lever will be worked only by one of the dogs on the bed, said lever being thrown only by the leftward dog, Fig. 4, and being cammed back to its initial position as soon as the leftward dog moves away on the reverse stroke of the table because its point did not pass the roller 80. Thus I provide a construction by which the controlling link 81 may be depressed, and the cross-feed operated, only at one extreme of movement of the reversible table. In particular construction I provide the link 81 with a rack 82 and arrange the point roller 80 in a'slidable frame 83 that carries a segmental pinion 84 engaging said rack and also a knurled head for eflecting adjustment through the rack'and segment. A clamp screw 86 holds the springy sides of the slidlng frame clamped in adjustment on the link.

The free end of the link 81 engages by a suitable slot-and-pin connection, a vertical slide member 87 that is fitted to slide in a vertical guide 88 fast on-the front plate.

This slide has secured to its body a stem 89 extending longitudinally of the guide with an adjusting stop-nut 90 threaded on the stem to bear against the under side of the guide when the slide is raised, a spring 91 encircling the stem between the slide and the guide normally to hold the former in raised position.

Adjustment of the nut 90 varies the upper limit of throw of the slide-member, the lower limit of which is substantially invariable (being the end of the-range of depression effected by lever 43) so that by a scale 92 on the guide the extent of each feed movement may be indexed.

At its upper end the slide carries a pawl 93 to engage the fine ratchet wheel 94 that is mounted fast on. the cross-feed shaft 70,

the pawl being equipped with a spring,

pressed throw-over point 95 to hold it with spring pressure either in or out of engagement with the ratchet wheel. Preferably the ratchet 94 is toothed at least as finely as to. give cross-feed movement in thousandths of an inch.

The hand wheel 97 is also mounted fast on the cross-feed shaft 70, and on the hub of such. wheel, between the spokes and the ratchet disk 94 is mounted a rotarily adjustable controller member 98, preferably a disk. This disk maybe clamped frictionally to the hand wheel to rotate with the cross-feed shaft, unless and until positively stopped, by means of radial blocks 99 extending through openings in the hand wheel hub and shaft from position to engage the inner circumference of the disk to position where the beveled inner ends of the blocks may be acted upon by the beveled end of the screw 100 threaded into the shaft. This disk carries a finger 101 arranged to lie over and close to the teeth of the ratchet wheel 94 so that such finger may, as the disk is rotated counter clockwise, lift the pawl 93 at a definite point in its travel, so as to throw theautomatic cross-feed out of operation and stop the progress of the grinding operation. Also the disk preferably carries a stop pro- .jection 103 spaced from the plate 101 by a distance such that just before the finger 101 finally lifts the pawl 93 out of engagement with the ratchet said projection will coaet with a stop 104 mounted in a studon the bed 10 and slidable by means of a finger-piece 105 out of the path of said projection 103. The one stop member 103 meets the other stop member 104 when the finger 101 has ridden far enough to be just back of the lowest tooth on the ratchet which can be engaged by the pawl, so that (regardless the setting of the stop-throw 90 which normally governs the throw of the pawl.) the pawl can advance the ratchet only the m1n1- mum distance of one tooth at a time as long as the two stop-members remain in engagement, the disk, under these circumstances merely slipping on the hand-wheel hub. If the stop part 104 is manually retracted, the controller-disk is free to advance its final tooth-length to completely disable the pawl. This construction is useful in permitting the workmen to make minimum finishing cutsone or more.

Either the disk or the hand wheel or both may be graduated, and where hand wheel graduations are employed I prefer that the hand wheel be provided with a rearwardly projecting flange near its periphery as at 106 and that a ring 107, peripherally graduated be secured thereon for rotary adjustment, to be fixed by a screw 108. This enables changes of zero-setting of the wheel to be made at will.

It will be made apparent to those skilled in the art that as the lever 81 is vibrated at the conclusion of each halfor full-reciprocation of the table, the pawl 93 will actuate the cross-feed of the grinding wheel, s'uch feed-shaft carrying with it the adjustable disk which, after completion of such transverse travel of the wheel as is indicated by the setting of the disk, may disable the pawl 91 to stop the operation by thrusting the finger 101 between the ratchet wheel and pawl.

While I have herein described in some detail. one specific embodiment of my invention, it will be apparent that many changes might be made therein without departure from the spirit of my invention within the scope of the appended claims.

\Vhat I claim is:

1. In a'machine of the character described, having a traveling table and a bed having front and end Walls provided with openings, closures for said front and end openings, table driving reversing and speed-changing gearing carried by said closure for the front opening, gearing-driving means carried by said closure for the end opening, said driving means and gearing being cooperatively related when said closures are in place, and being removable from the bedwith their respective closures.v

2. The combination of a hollow frame having an opening, a reciprocable table, a drive shaft supported by the frame, a gearframe detachab-ly supported on and extending onto the bed and removable through said opening; said gear frame carrying, in coacting relation, a shaft detachably connected with the drive shaft, reversing gearing, means for operating it, speed-change gearing, and means for operating it, said gearings being arranged one to drlve the other and the driving one to be driven from the gear-frame carried shaft.

3. The, combination of a hollow frame having an opening, a reciprocable table, a table-operated reversing lever, and a driving shaft, all carried by said frame; a gear frame detachably supported on and extend mg into said bed and removable, with the mechanisms internally carried thereby through said opening; and mechanisms carried by said gearing frame comprising a longitudinal shaft detachably connected to be driven from the driving shaft, a transverse shaft, reversing gearing for the latter, operating means for said reversing gearing extending into operative relation to said reversing lever; change-speed gearing-driven from said transverse shaft and arranged to drive the table, and means foroperating said change-speed gearing. Y

4. In a machine of the character described having a reciprocable table and a bed having front and end walls provided with respective openings, cover plates for said openings, a gear frame rigid with and including said front plate and extending into proximity with said end opening, table, driving and reversing gearing carried by said frame and removable with said front plate, including a longitudinal reversinggear shaft and transverse driving gear shafting, gearing driving means carried by said end-Wall plate and removable ther with, and coupling means between said driving means and the longitudinal shaft of the reversing gearing.

5. In a machine of the character described, comprising a reciprocable table and a bed therefor having front and end openings, cover plates for said openings, said feed shaft, of a shaft actuating ratchet and pawl mechanism, including a spring-rexturned depressible pawl-operating link, a table-actuated l1nk-depress1ng lever, and means for relating said lever and link foroperation of the latter to effect a cross-feed movement at both ends, or at one end only, of the table travel at will.

7. In a cross-feed mechanism, the combination with a shaft for cross-feeding, a link vibratable to actuate said shaft, and a rocking lever operable by table-travel, of means for effecting cooperation between the lever and link to effect a cross-feed movement when the lever is thrown in one only or in either direction.

8. In a grinder cross-feed control mechanism, the combination with a cross-feed shaft, ratchet, pawl, and spring-returned depressible link, a table reversing shaft, reversing dogs, and fast and loose levers on said shaft; of means for effecting cooperation between the loose lever and the link for lever-depression of the link and for link-camming of the lever, said means adjustable on said link to non-camming position. 1 9. In a. grinder crossfeed control mechanism, the combination with a cross-feed shaft, ratchet, pawl, and springreturned depressible link; the table reversing shaft, and reversing dogs; of a (logactuated loose lever having a pointed head, a cooperating projection on said link, and means for adjusting the link-projection longitudinally of the link.

10. 'In a grinder cross-feed control mechanism, the combination with a cross-feed .shaft, ratchet, pawl and spring-returned depressible link; a table reversing shaft and reversing dogs; of a dog-actuated loose a, pointed head, and longi-v lever havin tudinally ad3ustab1e frame on said link providing a projecting part for cooperation with the lever point.

11. In a grinder cross-feed control mechanism, the combination with a cross-feed shaft, ratchet, pawl, and spring-returned depressible link, the table reversing shaft,-

reversing dogs, of a dog-actuated lever having a pointed head, a slide frame on said link carrying a roller for cooperation with the leverpoint'and a gear part for co-' operation with a toothed part of said link to lirdjust the ,roller longitudinally of the lin 12. In a grinder cross-feed control mechanism, the combination with a cross-feed shaft, ratchet, pawl and spring-returned depressible rack-toothed link; a table reversing shaft, and reversing dogs of a dog actuated lever having a pointed head, a slide frame embracing said link, a gear "segment on said frame engaging the rack thereof,

a handle for said gear segment, means for' clamping said frame on said link and a roller on said frame for cooperation with said lever point. I

13. In a cross-feed mechanism' for grinders, the combination of a cross-feed shaft, a ratchet thereon, a table depressible said pawl, means for frictionally, connect-' ing said disk for rotation with the crossfeed shaft, a stop projection on'said disk, and a stop movable into and out of the path of said projection ata point to stop the progress of the disk before the latter has completely displaced the pawl.

.15. In a'grinder cross-feed mechanism, the combination with the cross-feed shaft, a ratchet fixed thereon, a ratchet operating pawl, table-controlled means for vibrating said pawl through a predetermined range of operation, a controlling part, means for frictionally engaging said controlling part .to rotate it with the ratchet, a pawl disabling finger carried by said controlling part, coacting stop parts on said controlling part and on a fixed portion'of the machine for stopping the rotation of said controlling part when the finger is in predetermined relation to the pawl, one of said stop-.parts being movable to disable such stopping mechanism.

RAYMOND C. MITCHELL 

